You’ve probably been told your whole life that water freezes at 32° F. But there’s more to it than that!
Water freezes in terms of temperature. But what’s fascinating is that water does NOT necessarily have to change from a liquid state to a solid state to be frozen.
Frozen water still in its liquid state is actually a real thing! It’s called “supercooled water.” And this supercooled water remains frozen as a liquid . . . until you add ice. Try this experiment for yourself and see what happens!
- bottled water (filtered or purified)
- crushed ice
- glass bowl
- glass cup
- a freezer
First, supercool your water.
Gently place the sealed bottles of water in your freezer. The key during this step is to move the bottles as little as possible. Leave them in the freezer for 2–3 hours.
Here’s what happens in the freezer.
The secret to supercooled water is in the molecules.
Solid–state molecules are locked together, and molecules in their gas state are few and far between. But water molecules move around a lot, and the secret to supercooling them is to keep them from moving. That way they won’t begin to attach and form together in a lattice–shaped structure. This is how the water “freezes” without actually taking on a solid form!
Water freezing is sort of like the process for putting a puzzle together. At the beginning, it can be overwhelming, complicated, and painfully slow. But those last ten pieces or so are cake. That’s how it is when water molecules freeze—slowly, slowly, slowly, and then all at once. Once they begin to attach and form structures, all the other molecules latch on quickly.
That’s why you’ll want to leave the water in the freezer just long enough to bring it to its freezing point. Just be sure to take it out before the molecules begin to find each other and bond together! For us, 2 hours and 45 minutes were just right!
Now, do super cool things with your water.
Carefully remove the water bottles from the freezer. You’re holding frozen liquid! Here’s what you can do with it:
- Pour the water over crushed ice in a glass bowl. The ice acts as an impurity to the water, giving the frozen liquid a “nucleus” to bond onto. You can watch the water freeze as you pour it, and make your own ice sculptures!
- Fill a clean glass cup with the supercooled water, and drop an ice cube in. Then watch while the ice cube instantly crystalizes before your eyes, turning the whole glass of water to ice.
- Or just hit the sealed water bottle firmly against a hard surface. The fast motion will give the molecules a chance to bond, and the bottle will freeze in your hand.